Materials Literature
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We have studied the dependence of magnetic properties on the carrier concentration of IV–VI diluted magnetic semiconductor Ge1−xMnxTe prepared by ionized-cluster beam technique. With increasing carrier concentration, the magnetic properties drastically change; saturation magnetization increases and coercive field decr…
High resolution He diffraction and scanning tunneling microscopy images of the fivefold surface of a single-grain i-AlPdMn quasicrystal are obtained showing an almost perfect quasicrystal order. Observed configurations can be identified within the framework of polyhedral models. The terrace terminations are found to b…
Abstract The reaction of toluene diisocyanate (TDI) with dimethylol propionic acid (DMPA) or diaminopentane sulphonic acid sodium salt (ES‐200) and other additives to form the structure of anionic polyurethane (PU) ionomer molecule has been proven by FT‐IR spectroscopy. In aqueous solution, the surface tension of anio…
Abstract A series of castor oil polyurethane/poly(methyl methacrylate) interpenetrating polymer networks (IPNs) and gradient IPNs, cured at room temperature, were prepared by a simultaneous IPN method. The polymerization processes were traced through IR techniques; results for the morphology and miscibility among mult…
Abstract Polymer degradation in solution has several advantages over melt pyrolysis. The degradation of low‐density polyethylene (LDPE) occurs at much lower temperatures in solution (280–360°C) than in conventional melt pyrolysis (400–450°C). The thermal degradation kinetics of LDPE in solution was investigated in thi…
$\ensuremath{\lambda}\ensuremath{-}(\mathrm{BETS}{)}_{2}{\mathrm{FeCl}}_{4}$ undergoes transitions from an antiferromagnetic insulator to a metal and then to a superconductor as a magnetic field is increased. We use a Hubbard-Kondo model to clarify the role of the ${\mathrm{Fe}}^{3+}$ magnetic ions in these phase tran…
Branchy alumina nanotubes (bANTs) have been shown to exist in aluminum oxide. Electron-beam evaporated 400 nm Al film on Si substrate is stepwise anodized in dilute sulfuric acid under the constant dc voltage 40 V at 10.0 °C. This electrochemical-anodizing route resulted in the formation of individual bANTs. Transmiss…
Bimodal (4 and 8 nm) mesoporous silicas with interconnected three-dimensional structure were synthesized by mild-temperature post-synthesis hydrothermal treatment of MCM-41 mesoporous materials in ammonia solution.
Epitaxially twinned (001)- , (118)- , and (104)-oriented La-substituted Bi4Ti3O12 (BLT) ferroelectric films have been grown by pulsed laser deposition on (001)- , (011)- , and (111)-oriented SrTiO3 single-crystal substrates, respectively, covered with SrRuO3. Well-defined (001)-oriented BLT films were grown at a subst…
The dielectric loss modes of SrTiO3 thin films deposited on different substrates are reported. Two dielectric loss modes around 165 and 75 K (at 10 kHz) with field-independent Tm are emphasized. The physical origin of the dielectric modes is discussed and is tentatively attributed to the motion of oxygen vacancies.
Unique affine extensions H aff 2 , H aff 3 and H aff 4 are determined for the noncrystallographic Coxeter groups H 2 , H 3 and H 4 . They are used for the construction of new mathematical models for quasicrystal fragments with tenfold symmetry. The case of H aff 2 corresponding to planar point sets is discussed in det…
The effects on the electrical properties of Si doping into Cu2O thin films deposited by reactive sputtering were studied. The hole density increased from 1×1015 to 1×1017 cm−3 with increasing Si content and the minimum resistivity obtained was 12 Ω cm. It was suggested that the electrically active acceptor with an act…
Experiments are presented elucidating how the evolution of foam microstructure by gas diffusion from high to low pressure bubbles can significantly speed up the rate of gravitational drainage, and vice versa. This includes detailed data on the liquid-fraction dependence of the coarsening rate, and on the liquid-fracti…
The random energy model (REM) has become a key reference model for glassy systems. In particular, it is expected to provide a prime example of a system whose dynamics shows aging, a universal phenomenon characterizing the dynamics of complex systems. The analysis of its activated dynamics is based on so-called trap mo…
A novel molecular spin ladder structure of a nickel dithiolate complex has been constructed using a supramolecular cation composed of anilinium and 18-crown-6.
Abstract Copolymerizations of styrene and the polyhedral oligomeric silsesquioxane (POSS)–styryl macromonomer 1‐(4‐vinylphenyl)‐3,5,7,9,11,13,15‐heptacyclopentylpentacyclo [9.5.1.1 3,9 .1 5,15 .1 7,13 ] octasiloxane have been performed with CpTiCl 3 in conjunction with methylaluminoxane. Random copolymers of syndiotac…
Individual large-diameter (∼3 to 5 nm) semiconducting single-walled carbon nanotubes (SWNTs) are found to exhibit ambipolar field-effect transistor (FET) behavior, with easily accessible n- and p-conduction channels by simple electrostatic gates. The effects of temperature and ultraviolet radiation on their electrical…
Recent experiments give evidence of a negative refractive index at microwave frequencies in a microstructured material. This discovery may allow some unique features associated with negative- refraction materials to be observed and applied. This letter describes the calculated results for photon tunneling via evanesce…
Photoluminescence (PL) from single silicon quantum dots have been recorded and spectrally resolved at room temperature. The Si nanocrystals (NCs) were fabricated using electron-beam lithography and reactive ion etching resulting in Si nanopillars that were subsequently oxidized to produce luminescent silicon cores. Th…
Neutron powder diffraction experiments on La2/3Ca1/3MnO3 over a broad temperature range above and below the metal-insulator transition have been analyzed beyond the Rietveld average approach by use of Reverse Monte Carlo modelling. This approach allows the calculation of atomic pair distribution functions and spin cor…